Other

Tadayoshi Takahara

Yoshio Sugimoto

Jun Chen

In order to precisely analyze thermal deformation of a substance which thermally shrinks over time, the amount of deformation of a substance is determined by separate steps of calculation of elasto-plastic deformation during temperature increase (step S ); calculation of creep deformation from the time when the temperature increase is completed till the time when the temperature decrease is started (step S ); and calculation of elasto-plastic deformation during the temperature decrease (step S ). When calculating the creep deformation, it is assumed that deformation due to the thermal shrinkage of the substance over time occurs simultaneous with the creep deformation, and strain rate is calculated as the time derivative of the total strain which is the sum of creep strain and the strain produced by thermal shrinkage. The creep deformation is then calculated by integrating the strain rate over the time from when the temperature increase is completed until the time when the temperature decrease is started.

Method for analyzing thermal deformation

A method for analyzing creep characteristic of a plastic molded substance is provided wherein the creep characteristic can be analyzed of an actual plastic molded substance having various shape and fastening conditions with high precision. The main stress value for each section of the analysis target is read out, hydrostatic stress &sgr; of each section is calculated from the main stress value, and the stress condition is determined to be tensile stress when &sgr; is positive and to be compressive stress when &sgr; is negative. Tensile or compressive characteristic value is assigned based on the stress condition at each section, and creep is calculated for a predetermined time period based on the characteristic value. By employing characteristic values depending on the stress conditions of each section, precision of creep characteristic analysis is greatly enhanced.

Growing community of inventors

Aichi-ken, Japan

Tadayoshi Takahara